"Five, four, three, two, one, and we have ignition," said Orbital ATK's mission control operator, as the rocket's engines lit up the chilly, gray morning and cheers erupted from spectators near the launchpad.

The mission is the eighth for Orbital ATK, which has a $1.9-billion (R24.7-billion) contract with NASA to resupply the orbiting outpost. SpaceX also sends its Dragon cargo ship to regularly re-stock the space lab.

Among the experiments on board is a satellite that will test how bacteria grows in microgravity, and determine the minimum amount of antibiotic needed to stop its growth.

Knowing how bugs will act during long-duration missions will help the US space agency, which hopes to send people to deep space in the coming decades, with a human mission to Mars sometime in the 2030s.

The cargo ship is also transporting 14 miniature satellites, known as CubeSats.

Cygnus should arrive at the orbiting outpost on Tuesday.

Astronauts will unload its contents, then repack it with trash so it can be shipped off in early December and burn up upon re-entry into Earth's atmosphere.

The current crew of six astronauts on duty at the space station include three Americans, one Italian and two Russians.